Motor system with magnet for a vehicle fuel pump

Abstract

A rotor for a brushless motor is resistant to degradation in alternative fuels and has desirable magnetic properties. A stator for a brushless DC motor includes coils wound both clockwise and counterclockwise around teeth of a back iron. Pairs of the coils are electrically connected in parallel.

1. A brushless electric motor system for an automotive fuel pump being capable of receiving an electrical current, the system comprising:
 a stator including windings wherein the electrical current flows through the windings to generate a magnetic field; and 
 a rotor, including a ring magnet, being configured to rotate in response to the generated magnetic field wherein the ring magnet comprises a rare earth magnet powder compression bonded with a high functionality thermoset binder such that the ring magnet exhibits a retained material crush strength of at least 90% after being soaked in E-85 fuel for approximately 400 hours. 
 
     
     
       2. The system of  claim 1  wherein the rotor has a magnetic field strength of at least 0.59 Tesla. 
     
     
       3. The system of  claim 1  wherein the rare earth magnet powder comprises neodymium-iron-boride. 
     
     
       4. The system of  claim 1  wherein the high functionality thermoset binder comprises an epoxy resin. 
     
     
       5. The system of  claim 1  wherein the high functionality thermoset binder comprises a phenol-formaldehyde resin. 
     
     
       6. The system of  claim 1  wherein the rotor is uncoated. 
     
     
       7. An automotive fuel pump system comprising:
 a motor having a magnet wherein the magnet comprises a rare earth magnet powder compression bonded with a high functionality thermoset binder such that the magnet exhibits a retained material crush strength of at least 90% after being soaked in E-85 fuel for approximately 400 hours. 
 
     
     
       8. The system of  claim 7  wherein the magnet has a magnetic field strength of at least 0.59 Tesla. 
     
     
       9. The system of  claim 7  wherein the rare earth magnet powder comprises neodymium-iron-boride. 
     
     
       10. The system of  claim 7  wherein the high functionality thermoset binder comprises an epoxy resin. 
     
     
       11. The system of  claim 7  wherein the high functionality thermoset binder comprises a phenol-formaldehyde resin. 
     
     
       12. The system of  claim 7  wherein the magnet is uncoated. 
     
     
       13. A method of forming a ring magnet for a rotor of a brushless electric motor, the method comprising:
 mixing a high functionality thermoset binder with a rare earth magnet powder; and 
 compression bonding the mixture to form a ring magnet for a rotor of a brushless electric motor such that the ring magnet exhibits a retained material crush strength of at least 90% after being soaked in E-85 fuel for approximately 400 hours. 
 
     
     
       14. The method of  claim 13  wherein the high functionality thermoset binder comprises an epoxy resin. 
     
     
       15. The method of  claim 13  wherein the high functionality thermoset binder comprises a phenol-formaldehyde resin. 
     
     
       16. The method of  claim 13  wherein the ring magnet has a magnetic field strength of at least 0.59 Tesla. 
     
     
       17. The method of  claim 13  wherein the rare earth magnet powder comprises neodymium-iron-boride.